我们都知道，nginx作为一个轻量级的web服务器，其在高并发下处理静态页面的优越性能是tomcat这样的web容器所无法媲美的，tomcat更倾向于处理动态文件，所以一个web应用可以通过nginx反向代理来实现动静分离，静态文件由nginx处理，动态文件由tomcat处理。
环境：
hadoop0.updb.com 192.168.0.100 nginx server
hadoop2.updb.com 192.168.0.102 tomcat server
hadoop3.updb.com 192.168.0.103 tomcat server
hadoop4.updb.com 192.168.0.104 tomcat server
hadoop5.updb.com 192.168.0.105 tomcat server
操作系统：
centos
Nginx版本：
nginx-1.7.6.tar.gz，采用源码编译安装
Tomcat版本：
apache-tomcat-7.0.56.tar.gz
JDK版本：
jdk-7u60-linux-x64.rpm
最终架构：
在弄明白架构之后，我们开始着手一步步来实现：
1、安装jdk + tomcat
hadoop2、hadoop3、hadoop4、hadoop5上安装jdk
rpm -ivh jdk-7u60-linux-x64.rpm
配置环境变量
[root@hadoop2 ~]# cat .bash_profile # .bash_profile # Get the aliases and functions if [ -f ~/.bashrc ]; then . ~/.bashrc fi # User specific environment and startup programs PATH=$PATH:$HOME/bin export JAVA_HOME=/usr/java/jdk1.7.0_60 export JRE_HOME=/usr/java/jdk1.7.0_60/jre export CLASSPATH=./:/usr/java/jdk1.7.0_60/lib:/usr/java/jdk1.7.0_60/jre/lib export PATH
使环境变量生效，并验证java环境是否安装成功
[root@hadoop2 ~]# . .bash_profile [root@hadoop2 ~]# java -version java version "1.7.0_60" Java(TM) SE Runtime Environment (build 1.7.0_60-b19) Java HotSpot(TM) 64-Bit Server VM (build 24.60-b09, mixed mode)
hadoop2、
hadoop3、hadoop4、hadoop5上安装tomcat，在webapps下创建测试目录shop和测试文件test.html和
test.jsp，测试文件中的内容为每个tomcat节点的主机名和IP地址，方便后边测试负载均衡
[root@hadoop2 ~]# tar xf apache-tomcat-7.0.56.tar.gz -C /opt/ [root@hadoop2 ~]# cd /opt/apache-tomcat-7.0.56/webapps/ [root@hadoop2 webapps]# mkdir shop [root@hadoop2 webapps]# vi shop/test.html this is hadoop2 root`s html! [root@hadoop2 webapps]# vi shop/test.jsp this is hadoop2 root`s jsp!
将tomcat的bin目录配置到环境变量，并使更改生效，并启动tomcat
## 设置环境变量 [root@hadoop2 ~]# cat .bash_profile # .bash_profile # Get the aliases and functions if [ -f ~/.bashrc ]; then . ~/.bashrc fi # User specific environment and startup programs PATH=$PATH:$HOME/bin:/opt/apache-tomcat-7.0.56/bin export JAVA_HOME=/usr/java/jdk1.7.0_60 export JRE_HOME=/usr/java/jdk1.7.0_60/jre export CLASSPATH=./:/usr/java/jdk1.7.0_60/lib:/usr/java/jdk1.7.0_60/jre/lib export PATH ## 使设置生效 [root@hadoop2 ~]# . .bash_profile ## 启动tomcat [root@hadoop2 ~]# startup.sh Using CATALINA_BASE: /opt/apache-tomcat-7.0.56 Using CATALINA_HOME: /opt/apache-tomcat-7.0.56 Using CATALINA_TMPDIR: /opt/apache-tomcat-7.0.56/temp Using JRE_HOME: /usr/java/jdk1.7.0_60/jre Using CLASSPATH: /opt/apache-tomcat-7.0.56/bin/bootstrap.jar:/opt/apache-tomcat-7.0.56/bin/tomcat-juli.jar Tomcat started.
测试tomcat是否正常工作，浏览器中访问，能够正常显示测试页面，表明工作正常。
2、安装nginx
[root@hadoop0 ~]# tar xf nginx-1.7.6.tar.gz -C /opt/ [root@hadoop0 ~]# cd /opt/nginx-1.7.6/ [root@hadoop0 ~]# ./configure --user=www --group=www --prefix=/usr/local/nginx --with-http_stub_status_module --with-http_ssl_module [root@hadoop0 ~]# make && make install
关于源码安装nginx，比较简单，如果过程中遇到问题可以到网上看看，都能找到答案，也可以在下面留言，一起讨论。
为了方便管理，为nginx编写服务脚本
[root@hadoop0 ~]# vi /etc/init.d/nginx
#!/bin/bash
#
#chkconfig: - 85 15
#description: this script use to manage nginx process.
#
#set -x
. /etc/rc.d/init.d/functions
procnum=`ps -ef |grep "/usr/local/nginx/sbin/nginx"|grep -v "grep"|wc -l`
start () {
if [ "$procnum" -eq 1 -a -f /usr/local/nginx/logs/nginx.pid ]; then
echo -n "Starting nginx:"
success
echo
else
/usr/local/nginx/sbin/nginx
if [ "$?" -eq 0 ]; then
echo -n "Starting nginx:"
success
echo
else
echo -n "Starting nginx:"
failure
echo
exit 4
fi
fi
}
stop () {
if [ "$procnum" -eq 1 -a -f /usr/local/nginx/logs/nginx.pid ]; then
/usr/local/nginx/sbin/nginx -s stop
if [ "$?" -eq 0 ]; then
echo -n "Stopping nginx:"
success
echo
else
echo -n "Stopping nginx:"
failure
echo
exit 3
fi
else
echo -n "Stopping nginx:"
success
echo
fi
}
case $1 in
start)
start
;;
stop)
stop
;;
restart)
stop
sleep 1
start
;;
reload)
if [ "$procnum" -eq 1 -a -f /usr/local/nginx/logs/nginx.pid ]; then
/usr/local/nginx/sbin/nginx -s reload
else
echo "nginx is not running!please start nginx first..."
exit 2
fi
;;
status)
if [ "$procnum" -eq 1 -a -f /usr/local/nginx/logs/nginx.pid ]; then
echo "nginx is running..."
else
echo "nginx is not running..."
fi
;;
*)
echo "Usage : nginx [ start|stop|reload|restart|status ]"
exit 1
;;
esac然后授予脚本可执行权限，并加入chkconfig开机自启动，并测试
[root@hadoop0 ~]# chmod +x /etc/init.d/nginx [root@hadoop0 ~]# chkconfig nginx on [root@hadoop0 ~]# /etc/init.d/nginx start Starting nginx: [ OK ] [root@hadoop0 ~]# /etc/init.d/nginx status nginx is running... [root@hadoop0 ~]# /etc/init.d/nginx stop Stopping nginx: [ OK ]
3、配置nginx，实现反向代理和动静分离
[root@hadoop0 ~]# cat /usr/local/nginx/conf/nginx.conf
user www www;
worker_processes 8;
error_log /usr/local/nginx/logs/error.log crit;
pid /usr/local/nginx/logs/nginx.pid;
events {
use epoll;
worker_connections 65535;
}
http {
include mime.types;
default_type application/octet-stream;
access_log /usr/local/nginx/logs/access.log;
charset utf-8;
sendfile on;
tcp_nopush on;
keepalive_timeout 60;
client_body_buffer_size 512k;
proxy_connect_timeout 5;
proxy_read_timeout 60;
proxy_send_timeout 5;
proxy_buffer_size 16k;
proxy_buffers 4 64k;
proxy_busy_buffers_size 128k;
proxy_temp_file_write_size 128k;
gzip on;
gzip_min_length 1k;
gzip_buffers 4 16k;
gzip_http_version 1.1;
gzip_comp_level 2;
gzip_types text/plain application/x-javascript text/css application/xml;
gzip_vary on;
## 配置反向代理的后端tomcat集群
upstream web_server {
server 192.168.0.102:8080 weight=1 max_fails=2 fail_timeout=30s;
server 192.168.0.103:8080 weight=1 max_fails=2 fail_timeout=30s;
server 192.168.0.104:8080 weight=1 max_fails=2 fail_timeout=30s;
server 192.168.0.105:8080 weight=1 max_fails=2 fail_timeout=30s;
}
server {
listen 80;
server_name 192.168.0.100;
root html;
index index.html index.htm;
## 网页、视频、图片文件从本地读取，且定义在浏览器中缓存30天
location ~ .*\.(htm|html|gif|jpg|jpeg|png|bmp|swf|ioc|rar|zip|txt|flv|mid|doc|ppt|pdf|xls|mp3|wma)$
{
expires 30d;
}
## js、css文件从本地读取，且定义在浏览器中缓存1小时
location ~ .*\.(js|css)?$
{
expires 1h;
}
## 动态文件转发到后端的tomcat集群
location ~ .*\.(php|jsp|cgi|jhtml)?$ {
proxy_pass http://web_server;
proxy_set_header Host $host;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Real-IP $remote_addr;
}
## 关闭访问日志
access_log off;
}
}4、测试反向代理的负载均衡和动静分离
在nginx的html目录下创建测试目录shop、测试文件test.html和test.jsp
[root@hadoop0 ~]# cd /usr/local/nginx/html/ [root@hadoop0 html]# mkdir shop [root@hadoop0 html]# vi shop/test.jsp this is nginx root`s jsp! [root@hadoop0 html]# vi shop/test.html this is nginx root`s html!
在浏览器中访问http://192.168.0.100/shop/test.html ，无论怎样刷新，页面都显示如下：
在浏览器中访问http://192.168.0.100/shop/test.jsp ，刷新几次，页面显示结果依次如下：
从结果来看，访问html静态文件时，返回的是nginx中的文件，而访问jsp动态页面时则是轮询后端的tomcat集群。至此，反向代理+动静分离已经实现。
5、接着我们来比较动静分离与单纯的反向代理的性能差异
首先安装模拟并发访问的压力测试工具
yum install httpd-tools -y
首先测试访问nginx代理
[root@hadoop0 ~]# ab -n 20000 -c 3000 Server Software: nginx/1.7.6 Server Hostname: 192.168.0.100 Server Port: 80 Document Path: /shop/test.html Document Length: 192 bytes Concurrency Level: 3000 Time taken for tests: 4.090 seconds Complete requests: 20000 Failed requests: 10907 (Connect: 0, Receive: 0, Length: 10907, Exceptions: 0) Write errors: 0 Non-2xx responses: 9994 Total transferred: 7563616 bytes HTML transferred: 2223840 bytes Requests per second: 4890.27 [#/sec] (mean) Time per request: 613.464 [ms] (mean) Time per request: 0.204 [ms] (mean, across all concurrent requests) Transfer rate: 1806.06 [Kbytes/sec] received Connection Times (ms) min mean[+/-sd] median max Connect: 64 303 338.8 172 3145 Processing: 98 241 131.0 211 1214 Waiting: 24 183 131.0 146 1203 Total: 201 544 381.9 403 3297
一共请求20000次，每次3000的并发访问，总共用的时间为4.090秒，吞吐量为1.806M/s,再看直接访问tomcat的结果：
[root@hadoop0 ~]# ab -n 20000 -c 3000 http://192.168.0.105:8080/shop/test.html Server Software: Apache-Coyote/1.1 Server Hostname: 192.168.0.105 Server Port: 8080 Document Path: /shop/test.html Document Length: 29 bytes Concurrency Level: 3000 Time taken for tests: 8.591 seconds Complete requests: 20000 Failed requests: 0 Write errors: 0 Total transferred: 5900000 bytes HTML transferred: 580000 bytes Requests per second: 2328.12 [#/sec] (mean) Time per request: 1288.594 [ms] (mean) Time per request: 0.430 [ms] (mean, across all concurrent requests) Transfer rate: 670.70 [Kbytes/sec] received Connection Times (ms) min mean[+/-sd] median max Connect: 0 256 824.9 0 7007 Processing: 1 70 148.9 38 3117 Waiting: 1 69 148.4 38 3117 Total: 4 327 866.9 40 8468
相同压力下，访问tomcat需要8.591秒，且吞吐量只有0.67M/s，可见nginx在处理静态页面上远优于tomcat。
结束语：我在实现了动静分离之后，想通过nginx自带的proxy_cache模块来实现nginx缓存自身代理的静态页面，发现无法成功缓存到，认为porxy_cache无法缓存作为静态服务器的nginx中的文件，但无法求证，如果您知道，拜托指点一二。拜谢!
本文出自 “勇敢向前，坚决向左” 博客，请务必保留此出处http://quenlang.blog.51cto.com/4813803/1570477
原文地址：http://quenlang.blog.51cto.com/4813803/1570477
